LAS VEGAS--One of the big complaints from consumers who buy General Motors cars that run on E85 ethanol is the lack of places to fill up.

General Motors CEO Rick WagonerPhoto by General Motors

GM CEO Rick Wagoner, in a meeting with reporters at the Consumer Electronics Show taking place in Las Vegas this week, says he has received hundreds of e-mails from customers who have bought such cars and are frustrated they can't find ethanol stations.

When GM started selling its flex-fuel cars, there were about 600 stations that sold ethanol in the U.S. Now there are about 1,400 stations.

But there are 170,000 filling stations in the country. The U.S. probably needs around 15,000 to 20,000 ethanol stations, he added.

To this end, GM has been working with big box retailers like Wal-Mart and Target to put ethanol pumps in.

"It has been remarkably difficult" to get pumps installed, he said. "We've been doing more work than I thought we would need to."

Corn ethanol also won't cut it for the long haul, if ethanol demand grows significantly. "To get beyond a certain level, it is going to have to go beyond grain-based in the U.S.," he said. The alternative could well be cellulosic ethanol.

Wagoner is making a rare appearance at CES to promote car electronics as well as GM's more fuel-efficient car. He'll be giving a keynote in less than an hour. During the speech, he will discuss a new prototype, the Cadillac Provoq, which comes with a solar panel on the roof to power the car's electronics, a hydrogen fuel cell, and a lithium-ion battery.

Speaking of lithium-ion batteries, Wagoner says reports that GM has delayed the Chevy Volt, a gas-electric car, are incorrect. The company still aims to come out with the car around 2010.

"Going for 2010 is a stretch, and it still is a stretch," he said, but the test results are coming up reasonably well.

The challenge largely lies in improving the batteries so that these cars will have a range consumers will find acceptable. The Volt is supposed to get around 300 miles before running out of gas and electricity. (The Volt drives on electricity and the gas engine recharges it while driving.)

GM, he added, continues to look at all-electric cars, but that's a tougher challenge and may come, at least from GM, only after electric-assist vehicles like the Volt are out. Automakers may also begin to push the "city car" concept. These cars only go about 120 miles on a charge, but are made for city driving.

The chief problem with the EV1, GM's canceled electric car from a few years back, was the range.

"If you want to drive around and not worry about it (running out of power), that hasn't worked yet," he said.

The EV1, however, didn't completely die. The nickel-metal-hybrid battery from the EV1 will be used in a Chevy Malibu hybrid.

And on the hybrid note, automakers will likely come out with a variety of hybrid drives, depending on the size of the car and its expected power.

"If hybrids take off, you will see a proliferation of different types of hybrid systems," he said.

Cars will continue to run on fossil fuels for a while, he added, but alternatives seem unavoidable. Emerging nations like China are buying more cars, which means greater fuel consumption, and environmental awareness is far higher.